This study enhances our understanding of the use of CAM by focusing on HMDS use, and specifically, the relationship between HMDS use and mental health. Although use of HMDS in general was not associated with psychiatric illness, bivariate analyses showed that the use of any psychoactive HMDS, St. John’s Wort, and melatonin was associated with the presence of psychiatric problems, and the use of garlic and bilberry was associated with the absence of psychiatric illness. However, the relationship between psychiatric illness and use of psychoactive HMDS in general was no longer significant in multivariate analyses, suggesting that multiple individual characteristics affect HDMS use.
Consistent with prior research (Roy-Byrne et al. 2005
), HMDS users and non-users did not differ in their rates of psychiatric medication use. Similar to that study, utilization of mental health services was not associated with HMDS use in general. It was, however, associated with the use of any psychoactive HMDS, melatonin, and bilberry. Furthermore, regardless of the presence or absence of a psychiatric diagnosis, one’s perceived need for mental health care and dissatisfaction with health care were strongly associated with HMDS use. These findings could be attributed to the possibility that individuals with greater perceived health needs tend to make greater use of all available health care services, both conventional and alternative, a finding also suggested by earlier research on the use of CAM from this survey (Unützer et al. 2000
) as well as other studies (Druss and Rosenheck 1999
The data indicate that 14% of those who use HMDS also use a psychiatric medication, and of those taking a psychiatric medication, 12% also use an HMDS. The increasing use of herbal remedies has generated the need for healthcare providers to familiarize themselves with the risks, side effects, and contraindications of more commonly used HMDS. However, not enough is known about the interactions between HMDS and conventional medication treatment (Ernst and Schmidt 2004
; Yager et al. 1999
). Although there is sufficient data to suggest significant drug–drug interactions involving HMDS (Cott 2001
), more research is needed to better understand these interactions. To compound the issue, a number of studies have shown that patients do not typically inform their physicians of their use of HMDS or other CAM modalities and such treatments are not consistently documented in the medical records (Druss and Rosenheck 1999
; Eisenberg et al. 1998
; Elkins et al. 2005
; Kessler et al. 2001
; Knaudt et al. 1999
). These findings underscore the need for clinicians to directly ask their patients about HMDS use (Mamtani and Cimino 2002
). Information about such use would also allow clinicians to explore potentially unmet mental health needs.
The findings indicate that individuals with a psychiatric disorder were significantly more likely to utilize St. John’s Wort and melatonin. However, the effectiveness of these compounds on outcomes is uncertain. The effectiveness of St. John’s wort for depression is still questionable because clinical trials have reported contradictory results. Past reviews and meta-analysis of the effectiveness of St. John’s wort concluded that it was more effective than placebo and as effective as standard antidepressants in treating depression (Gaster and Holroyd 2000
; Kim et al. 1999
). These studies, however, had several limitations including small sample sizes, inclusion of individuals with minor to moderate symptom severity, absence of an active antidepressant arm, and lack of data regarding long-term use. Since then, large, well-designed studies of St. John’s wort in major depression have found the herb to be no more effective than placebo (Hypericum Depression Trial Study Group 2002
). A more recent meta-analysis concluded that the evidence is inconsistent with older and smaller trials that were not restricted to major depression showing St. John’s wort to have a large effect on depression compared to placebo while larger trials that included major depression showed little to no effect (Linde et al. 2005
In regard to melatonin, clinical studies suggest that melatonin may be more effective than placebo in decreasing the amount of time required to fall asleep, increasing the number of sleeping hours, and boosting daytime alertness. There is some evidence that melatonin may improve depressive symptoms in seasonal affective disorder (Lewy et al. 1998
). Melatonin has also been shown to decrease insomnia in individuals with depression (Dalton et al. 2000
) and improve sleep latency and quality in schizophrenia (Sharmir et al. 2000
). However, these were small trials with a number of design limitations.
Although research on specific HDMS has increased over the past decade, there is a clear need for further research on the effectiveness of varying HMDS on mental health outcomes. Well-designed, controlled trials in select patient populations are needed before a clear conclusion can be reached about the effectiveness of any HMDS in mental health disorders. Randomized, controlled trials that compare specific compounds to both placebo and effective prescription medication are needed. The utility of HMDS as adjunctive therapies should also be examined.
Though the use of HMDS in the US has increased in the past decade, the precise reasons for this increase remain ambiguous. Self-treatment through the use of HMDS could represent an appealing option for those who fear stigmatization due to their perceived and/or diagnosed psychiatric disorder(s) (Charlton 2005
), who have not received appropriate mental health treatments (Young et al. 2001
) or who have experienced limited or no response to prescription psychiatric medication. The finding that HMDS users were more likely to be dissatisfied with their healthcare lends support to these explanations. HMDS may also be appealing in that they represent a relatively inexpensive alternative to conventional medicine in that the physician and associated fees can be by-passed. The increase in the use of HMDS may also be attributable to the increase in direct-to-consumer advertising, particularly the increase in Internet marketing of herbal medicines and dietary supplements. A 2002 study reported that 62% of Internet users sought health information online, and approximately half of these individuals sought information on alternative and complementary treatments (Fox and Rainie 2002
). These hypotheses are provided as potential explanations for the increased use of HMDS, however, there is little research addressing this issue. Further research is needed to understand the reasons for increased use of specific HMDS.
The study data was collected from 1997 to 1998 and may not reflect current trends in HMDS use. Given the rise in HMDS use over the last decade (Eisenberg et al. 1998
; Kaufman et al. 2002
; Kelly et al. 2005
), the data likely underestimate current use. The methodology likely underestimates use as well since participants were asked about medication they had taken at least several times a week for at least 1 month. The findings remain important, however, as even recent CAM studies do not focus specifically on HMDS use and mental health (Grzywacz et al. 2006
; Rossler et al. 2007
). We also cannot determine if use of particular HMDS represented an individual’s personal decision or a recommendation by a traditional or alternative health care provider.
The use of complementary and alternative medicine, including herbal medicines and dietary supplements, is widespread in American society. The use of HMDS warrants particular attention in persons with mental health problems or even perceived mental health problems as these individuals may be turning to HMDS use for treatment of their symptoms, though not to the exclusion of traditional treatments. However, those who seek both conventional and alternative care may not communicate their efforts to all of their providers. Considering the potential interactions between some HMDS and traditional medications, providers should talk with their patients about their use of HMDS (Werneke et al. 2006
). Why individuals who use HMDS seek such alternative treatments, how they get information about the vast variety of HMDS, and what the interactions are between HMDS and conventional treatments are all important questions that need to be addressed in order to better meet the needs of those who use HMDS and experience psychiatric problems.